Breeding the Fathead minnow (rosy red)

[Conner]

I'm planning on dumping a bunch of rosy reds into the bog filter I'm building for my pond. What's the likelyhood that I will be able to maintain a breeding population of rosies in my bog, with most of the offspring getting swept into the main pond to provide snacks for my pond fish (natives)?

 

[Gearhead]

Depends if it is an indoor pond or an outdoor pond. If its outdoor, they will only breed once a year, but if its a big enough bog there might be enough room for some fry to survive. If its indoor, you might be able to make them breed multiple times a year. Each spawn produces about 100-200 fry per female. Its pretty easy to keep them breeding though.

 

[hybridtheoryd16]

I'm planning on dumping a bunch of rosy reds into the bog filter I'm building for my pond. What's the likelyhood that I will be able to maintain a breeding population of rosies in my bog, with most of the offspring getting swept into the main pond to provide snacks for my pond fish (natives)?

Hey man when you get ready you can get a pound of fat heads from a couple of local places for 12.60 at one and 15.00 at the other.

A pound is supposed to be 360 3" fatheads. Or alot cheaper than lfs's.

Thats my #1 feeder.

 

[blurock]

How often will rosy's breed/reproduce if they are in a tank and you are controlling the photo-periods?

 

[Gearhead]

I havent tried it, but probly around once a month, mabye longer.

 

[Louie]

So are you saying that these hardy fish usually die with ammonia readings of .25ppm-.5ppm?

And only put into that situation for less than a couple of hours.

And I am not sure if you have been keeping fish very long or not but anytime you double a tanks stock, it will take some time for the bio-bacteria to grow enough to support that stocking/bioload.

And I only gave one example of when I have bought them by the pound. But I have also bought just 5dz and the same thing happens with the die off. Allthough the 5dz does not cause any ammonia load on the tank.

The place that I buy them from, has there holding tank which is 100g's total including filtration. And at any given time they have 12-15 pounds of fat heads in the tank ready for sale. And i beleive that is alittle more of a bio load than my 1 pound in a 55g and sump.

The only difference between the 2 set ups is the temperature. Mine being mid 70's and there's being mid 50's. So I am guessing that is the problem.

--------------------
70s isn't the problem . Maybe going from cool water to 70s fairly fast might be the problem but not 70s as far as being to warm.

I keep over a dozen outside in full shade (one of those 60 gallon pvc "ponds")but regardless when temps here averaged 100 PLUS till recently for last 3 - 4 months and didn't lose a single fish .

I have had them awhile forgot exactly how long but easily over 6 months.
Your temp is not high. I imagine the temps for them in shade was at mid high 80s during day . We do get close to daily inches of pouring rain.

They are big for rosy reds and look great but have never bred and now that added 1 M-2 F Florida dollar sunfish . I don't suspect they will.

 

[Louie]

I used to get thousands of fry in a backyard pond, untill I put a baby lmb in there. Now all but my koi have been eatin. For a while, i would get buckets of them in a 20 gal tank with 2 sponge filters. They would live for quite a while untill i used them all as feeders. It was kind of neat to have a mix of silver and rosy fry in the same tank. They would lay the eggs on the underside of lilypads, and a week latter there would be giant masses of fry all over the place.

----------------------
"and a week latter there would be giant masses of fry all over the place"

Oh nice.

Maybe they need cold winters to trigger breding in Spring/Summer ?.

 

[hybridtheoryd16]

--------------------
70s isn't the problem . Maybe going from cool water to 70s fairly fast might be the problem but not 70s as far as being to warm.

I keep over a dozen outside in full shade (one of those 60 gallon pvc "ponds")but regardless when temps here averaged 100 PLUS till recently for last 3 - 4 months and didn't lose a single fish .

I have had them awhile forgot exactly how long but easily over 6 months.
Your temp is not high. I imagine the temps for them in shade was at mid high 80s during day . We do get close to daily inches of pouring rain.

They are big for rosy reds and look great but have never bred and now that added 1 M-2 F Florida dollar sunfish . I don't suspect they will.

Hope your ready for a book lol
I should have already updated this thread with my new findings.

OK so after ready thru some info on the web about the (baitsaver) brand holding tanks that my local minnow spot holds theres in I found out that it takes cartridges as filter media in the side. And after further searching I found that these cartridges were carbon and a buffer for low PH.

So I had never checked the Ph of the water they were in because I had watched with my own eyes the guy filling these tanks with a water hose that was hooked to the same city water system as I used right down the road. And he even said ( I don't use any additives or anything. lol).

Well after checking I find out that the water in there holding tanks had a PH of 5.5-5.8. And our city water is close to a 8PH. As the light bulb went off in my head and I started to feel like a complete dumb ass. Basically I had been PH shocking these fish for 5 years and suffering massive die offs with every pound of minnows that I bought. As well as the ammonium/ammonia or deal.

See the bait saver holders are set up to lower the Ph so that they do not have to have any sort of a biological filter. Once the Ph drops below a certain point all of the ammonia is converted to ammonium which is nontoxic to fish. And if you couple this with a low temp like they do (50's) the minnows will never experience any ammonia.

So these minnows I was bringing home in a bucket. Were in water that had 8.0+ ppm ammonium reading and a Ph of around 5.5ph with a temp of around 50ish degree's.

And once I started the drip acclamation I was raiseing the temperature which would then convert the the ammonium to toxic ammonia. So the fish were going from zero ammonia to 8ppm+ ammonia in about a hour. And this as you already know would kill the hardiest fish there is.

And that is not even considering the stress that the rising temp and Ph levels were causing on the minnows.

Well my last 3 batches since I figured this mystery out have went alot better. Out of the pound (360 minnows) I get around 25 or so dead thru the 2 week period before another batch is bought.

I will take 25 over 300 any day of the week,

 

[Louie]

Oh that makes sense. Surprised your water PH is so high.

Ours is 8.0 to 8.4 tap and rain water. You wont angel fish or discus at fish farms lol.

I knew temps in 70s for prolonged wasn't killing them because the summer here was 100 degrees at 11am for 3 to 4 months now its a nice 80s. I have them in full shade but still warm. Daily massive rain pours help.

I should have stated that I purchased my rosy reds from a local fish farm thus ph was same as my back yard ponds.

You go through a lot of rosy reds . What fish do you feed them to ?

 

[hybridtheoryd16]

I feed fat heads to

1 large mouth bass
2 scomb payara
1 charax gibbous
1 unknown species ace cuda
3 yellow tail cuda's
3 hujeta characins
1 red tailed payara Tatauaia
and a fahaka puffer on occassion.

sadly they also eat alot of convict feeders as well.

my local bait shop loves me. lol